Natalie paddles in the morning mist; Tischer curls up between Lucas’ legs;

Tischer’s travel plans were solidified the moment my feet hit the beach. She had gained more than 10 pounds, spending much of the previous 97 days lying in the sun behind wooden bars, taunted by squirrels on my parents’ deck instead of running, swimming and cuddling with me.

She had been staying with my family because there was no way she’d ever sit still in the back hatch of my sea kayak for 1,200 miles. My 2010 expedition on Lake Superior wasn’t meant for a canoe, and a medium-sized dog wasn’t meant for a sea kayak.

Still, she was jaded, and it showed my first night back when she snubbed me, opting to sleep on my brother’s bed instead of mine. I promised her that on the next big trip, she was coming with me.

The Mississippi River is barely as wide as a 16-foot canoe when it leaves Lake Itasca in northern Minnesota. It was an especially shallow stream in early September 2013 when, for our first two days from the river’s source, I walked, dragged and lugged our heavily loaded canoe over beaver dams and through thick beds of wild rice. Tischer waded inquisitively between the banks, rock hopping and investigating long strands of vegetation curving gently in the soft current. As she explored, she only once looked up as she stood beside me midstream in only four inches of water, to see me sweating and exhausted.

Our goal was the Gulf of Mexico, 2,320 river miles downstream. Between here and there, we would paddle through a cross section of American culture. The river’s volume and use would increase; the distance between her steep, muddy banks would eventually widen; and the occasional bass-fishing boat would give way to barges the length of 5 football fields.

From the moment I started planning this trip, my main focus and concern was Tischer. Her experience would be different than mine. Life on the river was more likely to include long naps, big meals and lots of watching.

In the last of the fall warmth, Tischer eventually settled into the routine of being on the water. After two weeks of eating, sleeping and paddling outside, she began to adjust—or maybe she was just too exhausted to resist the program any longer.

She was my guard dog, instinctively spending her nights sleeping lightly, on alert for threats in the forests where our tent was tucked. Luckily, naptime came often during the many hours of paddling each day.

For the first 500 miles, the river, flanked by homes and docks, was frequently shallow and calm enough for her to wade alongside me. Below the Twin Cities, she found segments of uninhabited, vegetation-thick shoreline, and would run parallel to me, climbing over stumps or briefly swimming around thickets that extended into the river. After St. Louis, when the flow tripled, low water conditions presented miles-long sandbars, perfect for camping and unhindered running.

When hunter’s guns were silent and it wasn’t raining, her favorite spot in the boat was on top of the deck cover, which spanned the width of the bow. She rested here on her personal hammock, watching the changing landscape and feeling the rhythm of my paddle strokes. (She also took an accidental swim from this perch, flopping into the current as the result of an ill-placed paw at the 1,000-mile mark.)

She was normally calm and quiet, so when she started squirming or staring at me, I knew she needed a break from the boat. One time, in a hurry to get ashore, she launched off the bow seat toward the mud, punching a hole through the seat’s cane weave with her paw.

As reward for her tolerance and enthusiasm, whenever I ate out, so did she. At a riverside brewpub in Iowa, an unsympathetic server wouldn’t let me order a cheeseburger from the kid’s menu for her: “If you aren’t ordering it for your kid, then you can’t order it!” I begrudgingly relented and asked for a second burger special. Like the rest of the meals we shared—cheesy hash browns, egg sandwiches, pasta dinners—it was worth it, and it was our way of celebrating our effort together.

Tischer’s surrogate mother and my partner, Natalie, joined us two months into the trip, just before Tischer’s seventh birthday. Natalie’s seat as the bow paddler moved Tischer to the duff position, in the dead center of the boat. It was roomier than the bow and allowed Tischer to curl into the contours of the canoe better, but also meant that Natalie and I constantly had to counter her weight by shifting to the opposite side of the boat.

I cursed the cold and the wind often on this trip. When the waves got big, the barges too close, or I badly needed to use the bushes, so too did I curse Tischer back to the middle of our canoe. More often than I’d like to admit. Maybe extending her head over the side was her way of dealing with my stress. Unfortunately, in those moments, it only created more.

Mostly, though, our time on the Big Muddy was relaxed and full of adventure. Natalie first noticed the scratching, but Tischer was the one who excitedly discovered the stowaway mouse in a coiled rope; the mouse found itself relocated 11 miles downstream. To keep Tischer warm, we cuddled closer as a family in our sleeping bags during the below-freezing nights. Routine also dictated that when we landed on a sandbar to stretch, within seconds, we’d all be peeing side by side. It was river life.

We went through 29 locks and dams, and Tischer’s discomfort with them grew with each passing. The operator at Lock 5 sent down two dog treats, which she gobbled up, but she wouldn’t be seduced so easily. The final lock was the worst, eerily creaking and groaning as we dropped nearly 40 feet within its massive concrete chamber. Not knowing how horrifying it would sound but realizing Tischer’s anxiousness at this point, I had moved my large dry bag and slid her back between my legs for the 30-minute lowering. My closeness didn’t help much, unfortunately.

To boot, the Old River Lock led us away from the Mississippi and into the Atchafalaya River Basin, the largest swamp in the U.S. It was dark and I was suddenly paranoid, worried about alligators lurching out of the shallows at Tischer. Easy domestic prey, I figured.

My fears subsided over the next few days, as the temperatures remained too chilly and cloudy for gators to be active. Three days before we reached the open ocean, however, that changed. Natalie spotted the first one, barely four feet long, sunning itself on the steep bank. I stared, open-mouthed. It was my first gator sighting, and although Tischer didn’t notice it before it slid back into the water, all I could think about was the possible danger to her.

Within 30 minutes, another one—this time bigger—lay camouflaged in leaves and mud. By the time we spotted the next gator (thoroughly dead and longer than our canoe even with its head cut off) my anxiety level was through the roof! Natalie could sense this as, time after time, I suggested we just pee from the canoe instead of stopping on shore. “We can’t not get out of the boat until we reach the Gulf,” she offered, which was hardly reassuring.

The trip’s last days turned out to be gorgeous and gator-free. Finally, the Louisiana weather delivered what we had expected and our skin again felt the sun’s warmth. Passing Morgan City, we had many on-water visitors from other motorized boats, surprised to see a canoe with a dog among ocean-going vessels.

Our last campsite, five miles from the mouth of the river on the only spot of solid land left, was covered in seashells. It was December 18, 102 days since leaving the headwaters. We wrapped a strand of Christmas lights around our paddles and before the battery pack died, I snapped a photo of Tischer sitting in their glow while the sun set on the ocean behind her.

I have no doubt that she enjoyed her time on the river. From sand dunes to winery tours, it was wildly packed with new smells, scenes and people, and allowed her to play unhindered for three months. She became a complete river dog; short of joining a coyote pack, she couldn’t have been freer. More than these things, though, she loved the river life because she was with me. I knew that because I felt the same way about her.

After our brief post-trip time in New Orleans, we hit the road for the winterized northland, Tischer snug on her blanket in the back seat. It was obvious that she was mesmerized by our speed and looking for a gunwale to rest her chin on.

We arrived at a Christmas Eve gathering to the surprise of family and friends. As we walked in, my mother exclaimed to the filled room, “You guys! This dog just canoed the entire Mississippi River!”

Bemused, Natalie and I looked at each other, and then joined in praising Tischer’s accomplishment.

Lucas Will is an outdoor educator, writer and all-around waterman. He adopted Tischer from a rescue shelter in Portland, OR 7 years ago. Together with Natalie, they live aboard a sailboat on Lake Superior.